Recently, The width of the segment used the shield tunneling method tends to become wider. When the segment rings are jointed staggeringly, the shearing force generated by the splice effect will act on the longitudinal joint bolt. The bending stress generated by this shearing force is deemed to increase and concentrate on the end of the segment according to the increase of the width of the segment.
The object of this study is to analyze the relationship between the width of the segment and the distribution of the bending stress experimentally, by using four types (width 300, 400, 500, 600mm) of flat-type RC segment models.
Through this experiment, we found that the increase of the segment-width causes the concentration of the bending stress at the end of the segment. Therefore when designate the segment wider than 1200mm, it is necessary to examine this increase of the bending stress and consider the effective countermeasure.